DE3938978A1 - MORE COLOR RECORDING MATERIALS - Google Patents

Description

The invention relates to silver salt-free, photosensitive and / or heat-sensitive recording materials for the multicolor recording, e.g. for the production suitable for color copies.

Silver salt photography has been the most widely used to date Production of multicolor images used as they high sensitivity, high image quality and the ability provides for gradation reproduction. On the other hand, the Silver salt photography has the disadvantage of a complicated Processing, which after the imagewise exposure the Development in a developer bath, followed by the conversion of the remaining silver halide into a water-soluble silver complex salt or in a light-stable Silver salt.

To remedy this disadvantage, for example dry type photographic recording materials (see, for example, JP-A-59-48764), photographic Dye-transfer type recording materials (see for example GB-A-2 49 530 and US-A-20 20 775, 20 04 625, 22 17 544, 22 55 463 and 26 99 394) and photographic Silver dye bleach type recording materials (see, e.g., U.S. Patent No. 2,844,574).

Recording systems such as e.g. electrophotographic Systems, thermal transfer systems and Inkjet systems, the multicolor Recording mechanisms are in devices been used with recording materials that no Silver salts included. However, these systems have the Disadvantage that the device is large, the Record fidelity is poor and considerable effort is necessary to change variables.  

Heat sensitive recording systems have this Disadvantages do not work and if they are practical Multicolor recording could be used they are easy to handle. There are already procedures under Use of heat-sensitive recording systems known in which several color-forming units are simple be generated successively by the added heat energy increases to a color mixture and To achieve change of hue (see e.g. JP-B-51-19989, corresponding to US-A-3895173, JP-B-52-11231, JP-A-54-88135, JP-A-55-1 33 992 and JP-A-55-1 33 992). Other processes use a decolorization mechanism which a decolorizing agent becomes effective at the same time when color forming units at temperatures above the Heat sensitivity temperature make colors, and at the color units, the colors at low temperature are discolored (see, e.g., JP-B-50-17868, according to US-A-38 43 384, JP-B-51-5 791, JP-B-57-14318 and JP-B-57-143199). The main issue with color hard copies However, this type is that only a small Number of colors can be generated.

Recording materials in which heat-sensitive and photosensitive color systems are combined, are used e.g. in U.S. Patent Application 07 / 117,606, JP-A-63-1 72 681, JP-A-63-45 084 and JP-A-63-1 34 282 described. With these multicolour Recording materials succeed, the above To improve defects in some way. So be Units in which a combination of diazo compound and couplers yield a color-forming component, and / or Units in which a combination of leuco dye and color developers form a color-forming component, as color-forming layers in recording materials used in which at least one color-forming unit provided on each side of a transparent support is different and the color-forming units Give shades.  

However, one uses several layers of such color forming units on the same side of the Recording material, there are problems in terms of Shelf life and image density, so that a transparent support is used and the color-forming Layers are provided on both sides of the carrier. There is thus a fundamental limitation in that non-transparent support for these Materials are unsuitable; it is also disadvantageous that during manufacture a new opaque Layer must be created.

The object of the invention is to provide a multicolour Recording material, e.g. a two-color Recording material to provide, which also in the Cases where the color-forming layers on the same Side of the carrier are arranged, excellent Shelf life and color density.

The subject of the invention is:

1. A two-color recording material on a carrier

• a) a photosensitive, heat-sensitive color-forming layer comprising,
  (i) microcapsules containing a leuco dye which gives a color upon oxidation, and a photooxidant, and
  (ii) a reducing agent; and
• b) a heat-sensitive color-forming layer with a color forming temperature different from that of Glass transition temperature of the microcapsule walls is different, containing one Electron donor leuco dye containing one of the leuco dye in the photosensitive, heat-sensitive layer different  Tint produces, and one Electron acceptor compound associated with the Electron donor leuco dye with color formation reacts;

2. A multicolor recording material that is on a Carrier:

• a) a photosensitive, heat-sensitive color-forming layer containing
  (i) at least two types of microcapsules, each containing a leuco dye which develops a color upon oxidation, and a photooxidant, and
  (ii) a reducing agent, wherein the polymer walls of the at least two types of microcapsules have different glass transition temperatures and the leuco dyes contained in the microcapsules give different hues to each other; and
• b) a heat-sensitive color-forming layer with a color forming temperature different from the Glass transition temperatures of the microcapsule walls is different, containing one Electron donor leuco dye containing one of the leuco dye in the photosensitive, heat-sensitive color-forming layer different hue results, and one Elektronenacceptorverbindung, which with the Electron donor leuco dye with color formation reacts; and

3. A multicolor recording material that is on a Carrier:

• a) a photosensitive, heat-sensitive color-forming layer containing
  (i) at least two types of microcapsules, each containing a leuco dye which generates a color upon oxidation, and a photooxidant, and
  (ii) a reducing agent wherein the leuco dyes contained in the microcapsules give different hues to one another and the photooxidants contained in the microcapsules are activated by actinic light of different wavelengths; and
• b) a heat-sensitive color-forming layer with a color forming temperature different from the Glass transition temperatures of the microcapsule walls is different, containing one Electron donor leuco dye, which has a from the leuco dye in the photosensitive, heat-sensitive color-forming layer different hue results, and one Elektronenacceptorverbindung, which with the Electron donor leuco dye with color formation responds.

The following are the manufacturing process for the Inventive multicolor recording materials as well as the process for the production of multicolored Pictures using these materials closer explained.

The preferred capsules for the photosensitive, heat-sensitive color-forming layers are capsules, where the contact between the substances within or outside the capsules at normal temperature through the Separating effect of the microcapsule walls is prevented, and which become permeable to these materials when they be heated above a certain temperature. The Temperature at which the permeability can begin  by suitable selection of the material for the capsule walls, the capsule nucleus substance and additives are arbitrarily set become. The temperature at which the permeability begins, in this case, as the glass transition temperature the capsule wall.

With a view to adequate thermal recording the glass transition temperature is preferably 60 to 200 ° C, especially 70 to 150 ° C, to a fast Response to heating by a thermal head too achieve.

By choosing the capsule wall material, the Glass transition temperature of the capsule wall can be adjusted. Suitable wall materials according to the invention are e.g. Polyurethanes, polyureas, polyamides, polyesters and Polycarbonates, polyurethanes and polyureas are particularly preferred.

The microcapsules are prepared by adding the Nuclear material containing photoimageable substances contains, e.g. the leuco dye used in the oxidation gives a color, and the photooxidant, emulsified and then walls of a polymer substance around the emulsified ones Oil droplets around trains. In this case, the the wall forming reactants within and / or added outside the oil droplets.

When the microcapsule walls are in the form of microencapsulation a polymerization of the reactants within the Oil droplets are produced, obtained in a short time Production time preferred capsules for the Recording materials that have a uniform Particle size and excellent storage properties in have fresh condition.

Microencapsulation process and starting compounds for this purpose are e.g. in US-A-3,726,804 and 3,796,696  described. In the case of using polyurethanes or polyureas as capsule wall material is mixed e.g. a polyisocyanate and a second compound, the with the polyisocyanate to form capsule walls reacts (e.g., a polyol or polyamine) with the aqueous one Phase or in the oily liquid that is encapsulated is to be, and emulsified and dispersed in water, whereupon the temperature is raised so that the Polymer formation reaction at the oil interface under Training of microcapsule walls takes place.

The glass transition temperature of the capsule walls can be within a wide range by appropriate choice of Polyisocyanate, which is the first wall-forming substance represents, and the polyol or polyamine, the second wall forming substance is set.

As organic solvents in which the mentioned image-forming substances are dissolved are suitable, e.g. high boiling oils. Specific examples of such Solvents are phosphate esters, phthalate esters, Acrylic acid esters, methacrylic acid esters, others Carboxylic acid esters, fatty amides, alkylated biphenyls, alkylated terphenyls, alkylated naphthalenes, diarylethanes and chlorinated paraffins.

Low boiling point co-solvents can be used be added to said organic solvents, e.g. Ethyl acetate, isopropyl acetate, butyl acetate, Methylene chloride and cyclohexanone.

The aqueous phase may contain protective colloids and wetting agents be added to the emulsified oil droplets stabilize. Generally speaking, they are suitable water-soluble, high-molecular substances as Protective colloids.  

The volume average of the microcapsule size is preferably not more than 20 μm, in particular not more than 4 μm, in terms of the desired image resolution and the Handling properties.

The leuco dyes, which in the oxidation of a color Training are essential components of the mentioned image-forming materials. They represent reduced Forming dyes with one or two Hydrogen atoms, whereby the color formation takes place, when these hydrogen atoms are removed, or in In some cases, when electrons are supplied. These Leuco dyes are essentially colorless or light colored, so that in the oxidation and color formation Pattern arises. The oxidation takes place in the presence at least one photooxidant. The Photooxidant is by irradiation with light activates and then reacts with the leuco dye below Generation of a color image against the background of the unchanged material that has not been exposed.

Leuco dyes, according to the mechanism mentioned Produce colors are e.g. in US-A-3,445,234 described. These include, for example:

• ( 1 ) Aminotriarylmethane
• ( 2 ) aminoxanthene
• ( 3 ) aminothioxanthene
• ( 4 ) amino-9,10-dihydroacridine
• ( 5 ) Aminophenoxazine
• ( 6 ) aminophenothiazine
• ( 7 ) aminodihydrophenazine
• ( 8 ) aminodiphenylmethane
• ( 9 ) leukoindamine
• ( 10 ) Aminohydrocinnamic acid (cyanoethane, leukomethine)
• ( 11 ) hydrazine
• ( 12 ) indigoid leuco dyes
• ( 13 ) Amino-2,3-dihydroanthraquinone
• ( 14 ) Tetrahalogeno-p, p'-biphenol
• ( 15 ) 2- (p-Hydroxyphenyl) -4,5-diphenylimidazole
• ( 16 ) phenethylaniline

The parent dyes are obtained by removing one hydrogen atom from the leuco forms ( 1 ) to ( 9 ) and two hydrogen atoms from the leuco forms ( 10 ) to ( 16 ).

Specific examples are leucocrystal violet,
Tris (4-diethylamino-o-tolyl) methane,
Bis (4-diethylamino-o-tolyl) phenylmethane;
Bis (4-diethylamino-o-tolyl) 2-thienyl-methane,
Bis (2-chloro-4-diethylaminophenyl) phenylmethane;
2- (2-chlorophenyl) amino-6-N, N-dibutylamino-9- (2-methoxycarbonyl) phenylxanthene,
2-N, N-dibenzylamino-6-N, N-diethylamino-9- (2-methoxycarbonyl) phenylxanthene,
Benzo [a] -6-N, N-diethylamino-9- (2-methoxycarbonyl) phenylxanthene,
2- (2-chlorophenyl) amino-6-N, N-dibutylamino-9- (2-methylphenylcarboxamido) phenylxanthene,
3,6-dimethoxy-9- (2-methoxycarbonyl) phenylxanthene,
3,6-diethoxyethyl-9- (2-methoxycarbonyl) phenylxanthene,
Benzoylleukomethylenblau and
3,7-bis (diethylamino) phenoxazine.

According to the invention, two or more types of Leuco dyes are encapsulated. The amount of Leuco dye in the photosensitive, heat-sensitive color forming layer depends the desired color density of the image and can be selected by the skilled person be easily determined.

Chemical compounds that are normally inactive, however, when irradiated with actinic light, e.g. visible light, UV, IR or X-rays, Leuco dyes oxidize as photooxidants  which are preferred in the inventive color-forming Materials are used.

Typical photooxidants are lophin dimers, e.g. 2,4,5-triarylimidazole dimer (JP-B-62-29 728, corresponding to US-A-42 47 618, and JP-B-63-2 099, correspondingly US-A-43 11 783 and 42 52 887); Azides, e.g. 2-azidobenzoxazole, benzoyl azide and 2-azidobenzimidazole (US-A-32 82 693); Pyridinium compounds, e.g. 3'-ethyl-1-methoxy-2-pyridothiacyanine perchlorate and 1-methoxy-2-methylpyridinium-p-toluenesulfonate (US-A-3615568); organic halogen compounds, e.g. N-bromosuccinimide, tribromomethylphenyl sulfone, 2-trichloromethyl-5- (p-butoxystyryl) -1,3,4-oxadiazole and 2,6-Ditrichloromethyl-4- (p-methoxyphenyl) triazine and the in Nihon Syasin Gakkai 1968-nen Syunki Kenkyu Happyokai Koenyoshi-syu (Proceedings of the 1968 Annual Spring Conference of the Japanese Photographic Society), p. 55 (1968) Azidpolymeren described. From these materials are lophine dimers and organic halide compounds preferred and their common application is with regard to especially on achieving high sensitivities prefers.

The leuco dye and the photooxidant become in a molar ratio of 10: 1 to 1:10, preferably 2: 1 to 1: 2, for the preparation of the inventive image-forming materials mixed.

Stable images can be used in a precise way with the produced image-forming materials according to the invention are heated by heating after the exposure and the picture generated or by total exposure after generation of a stable latent image by heating. The thermal Recording mechanism (or fixing mechanism) of Imaging materials according to the invention thus comprise contacting photooxidant and Reducing agent through the microcapsule walls by heating  and deactivating the oxidizing agent by acting of the reducing agent also where e.g. the Photooxidant has been activated. These Reducing agents are referred to as radical scavengers, which the free radicals of the activated Intercept photooxidant.

Specific examples of reducing agents are aminophenols and hydroquinones having a hydroxyl group on the benzene ring and at least one further hydroxyl group or amino group in a different position of the benzene ring (US-A-30 42 515), cyclic phenylhydrazides (JP-B-62-39 728, according to US-A-42 47 618), guanidine derivatives, Alkylenediamine derivatives and hydroxylamine derivatives. These can be singly or as combinations of two or several are used, with no restriction provided the reducing agents have reducing properties, which are the so-called Influence oxidant.

The abovementioned reducing agents may be used in the image-forming materials of the invention e.g. dispersed with a sand mill as solids or in dissolved and emulsified and dispersed in an oil. in the general is a water-soluble high molecular weight Substance used as a protective colloid, if the Reducing agent dispersed as a solid or emulsified and dispersed.

The molar amount of the reducing agent is preferably one to a hundred times, especially the five to Twenty times the total molar amount of the photooxidant.

In addition to the photooxidants can also conventional sensitizers, UV absorbers and Antioxidants are used. Further, after At will adjuvants are used to thermal Regulate recording or fixation. such  Auxiliaries lower the melting point of the various Components of the system or lower the glass transition point the capsule walls.

Examples of such auxiliaries are Phenolic compounds, alcohols, amides and sulfonamides. These can be added to the core materials or used as dispersions outside the microcapsules become.

The photosensitive, heat-sensitive layers are obtained by adding a carrier with a Dispersion of microcapsules containing leuco dyes and Photooxidants contain, as well as reducing agents coated.

Binders, pigments, waxes, metal soaps or wetting agents can be added to the dispersions mentioned at this time. The order quantity (solid constituents) is 3 to 30 g / m ² , preferably 5 to 20 g / m ² .

Examples of electron donor leuco dyes used in the heat-sensitive color forming layers are used may be triarylmethane, diphenylmethane, xanthene, Indolylphthalide, azaphthalide and spiropyran compounds.

Special examples are
3,3'-bis -6-dimethylaminophthalide (p-dimethylaminophenyl)
3,3-bis (p-dimethylaminophenyl) phthalide,
3- (p-dimethylaminophenyl) -3- (1,3-dimethylindol-3-yl) phthalide and
3- (p-dimethylaminophenyl) -3- (2-methylindol-3-yl) phthalide as triarylmethane compounds;
4,4'-bis-dimethylaminobenzhydrinbenzylether,
N-Halogenphenylleukoauramine and
N-2,4,5-trichlorophenylleukoauramine as diphenylmethane compounds;
Rhodamine B-anilinolactam,
lactam rhodamine (p-nitroanilino)
2-benzylamino-6-diethylaminofluoran,
2-anilino-6-diethylaminofluoran,
3-diethylamino-7,8-benzofluoran,
3,6-Dimethoxyfluorane and
2,7-di-n-hexyl-3,6-dimethoxyfluoran as xanthene compounds;
3,3-bis (1-ethyl-2-methylindole-3-yl) phthalide,
3,3-bis (1-octyl-2-methylindol-3-yl) phthalide,
3- (2-Ethoxy-4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) phthalide and
3- (2-Ethoxy-4-diethylaminophenyl) -3- (1-octyl-2-methylindol-3-yl) phthalide as indolylphthalide compounds;
3- (2-Ethoxy-4-diethylaminophenyl) -3- (1-octyl-2-methylindol-3-yl) -4- (or 7) -azaphthalide and
3- (2-Ethoxy-4-diethylaminophenyl) -3- (1-ethyl-2-methylindol-3-yl) -4- (or 7) -azaphthalide as azaphthalide compounds;
and 3-methylspirodinaphthopyran,
3-ethylspirodinaphthopyran,
3,3'-Dichlorspirodinaphthopyran,
3-Benzylspirodinaphthopyran and
3-methylnaphtho- (3-methoxybenzo) spiropyran as spiropyran compounds.

The amount of electron donor leuco dye in the heat-sensitive color forming layer depends the desired color density of the image and can be selected by the skilled person be easily determined.

Examples of electron acceptor compounds used in the heat-sensitive color forming layers are used, are phenolic compounds, organic acids and theirs Metal salts and oxybenzoic acid esters.

Specific examples of these compounds are
2,2-bis (4'-hydroxyphenyl) propane (bisphenol A),
2,2-bis pentane (4'-hydroxyphenyl)
2,2-bis (4'-hydroxy-3 ', 5'-dichlorophenyl) hexane,
1,1-bis (4'-hydroxyphenyl) propane,
1,1-bis (4'-hydroxyphenyl) cyclohexane,
2,2-bis (4'-hydroxyphenyl) propane,
1,1-bis (4'-hydroxyphenyl) butane,
1,1-bis pentane (4'-hydroxyphenyl)
1,1-bis (4'-hydroxyphenyl) hexane,
1,1-bis (4'-hydroxyphenyl) heptane,
1,1-bis (4'-hydroxyphenyl) octane,
1,1-bis (4'-hydroxyphenyl) -2-methylpentane,
1,1-bis (4'-hydroxyphenyl) -2-ethylhexane,
1,1-bis (4'-hydroxyphenyl) dodecane, p-phenylphenol,
3,5-diphenylphenol and cumylphenol as phenolic compounds;
3,5-di- α- methylbenzylsalicylic acid,
3,5-di-tert-butylsalicylic acid,
3- α, α- dimethylbenzylsalicylic acid,
4- β -p-methoxyphenoxyethoxysalicylic,
4- b- p-methoxyphenoxyethoxysalicylic acid and the polyvalent metal salts (eg, zinc and aluminum salts) of these acids;
and benzyl p-hydroxybenzoate and
2-ethylhexyl p-hydroxybenzoate as oxybenzoic acid ester.

The proportion of electron acceptor, based to the electron donor leuco dyes preferably 50 to 800, in particular 100 to 500 weight percent.

The electron donor leuco dyes and Electron acceptor compounds are each separated using a ball mill or sand mill on one Particle size of a few microns dispersed and then mixed together to form a heat-sensitive Produce color forming liquid. Each of the components can also be encapsulated. The electron donor Leuco dye and the electron acceptor compound are generally put together in a solution of a water-soluble high molecular weight material, e.g. one Polyvinyl alcohol solution, dispersed, whereupon if necessary sensitizers added. The Sensitizers can be used either simultaneously with the Electron donor leuco dye, the Electron acceptor compound or both Electron donor leuco dye and the  Electron acceptor compound added and dispersed become.

The resulting dispersions may optionally Binders, pigments, waxes, metal soaps or surfactants be added.

The heat-sensitive color-forming layers can be prepared by applying a heat-sensitive coating liquid obtained in the manner described above to a support. The application amount of the heat-sensitive color-forming layer (solid components) is preferably 2 to 10 g / m ² .

According to the invention, a heat-sensitive Color forming layer in addition to the photosensitive, heat-sensitive color forming layer, whereby the advantage is that the multicolor recording easier than using only one type Color-forming layer.

Suitable carrier materials for the inventive Recording materials are papers about the Total area from paper webs to cardboard, regenerated Cellulose, cellulose acetate, cellulose nitrate, Polyethylene terephthalate, polyethylene, polyvinyl acetate, Polymethyl methacrylate and polyvinyl chloride.

Applying the photosensitive, heat-sensitive Color forming layer and the heat-sensitive Color forming layer on the support can be arbitrary Coating methods are carried out, e.g. by airbrush, Curtain, doctor blade, roller, dip, wire rod, casting, Engraving, spin coating and extrusion coating.

In the following, the multicolor Recording methods and methods for producing good Multicolor pictures explained in more detail.  

In cases where the photosensitive, heat-sensitive color forming layer contains a plurality of microcapsule types having different glass transition points, the glass transition points of the mixed microcapsules from the low temperature side are T _1, T ₂ , ... T _n and the hues produced by the contained leuco dyes , C ₁ , C ₂ , ... correspond to C _n . In the case of heat sensitive color forming layer, the color-forming temperature is due to the electron-donating leuco dye and electron accepting T ₀ and the hue corresponds C _0th

For example, printing is performed using a thermal block at a printing temperature T _a , where T _{1 is} T _a < T ₂ , forming a latent image followed by printing at a printing temperature T _b , where T ₂ T _b < T ₃ of a latent image, and this process is repeated to form latent images in the photosensitive, heat-sensitive color forming layer, followed by subjecting the material of a total exposure, so that the hues C ₁ , C ₂ . , , C _{n are} generated, and by printing at a temperature T , where T ₀ T , the color tone C _{0 is} generated.

In this case, it is desirable that T _n < T ₀ to avoid color mixing due to unwanted color formation. Furthermore, the difference between the glass transition points of the microcapsules in each case between T ₁ and T ₂ , T ₂ and T ₃ ,. , , and T _{n -1} and T _{n are} preferably 5 ° C or more.

Two-color images can of course after the same Process are produced. In this case, the Glass transition points of the turn of the microcapsules, which in the photosensitive, heat-sensitive Color forming layer are contained, preferably in essentially the same. If they are different, the thermal processing is preferably at a  Temperature above the higher glass transition point carried out.

When the color-forming wavelengths (wavelengths of light used for color generation with the microencapsulated leuco dyes) are different ( λ ₁ , g ₂ , ..., λ _n ), it is possible to independently generate each hue, which is preferable. The hue C ₁ is thus produced by exposure to light of wavelength λ ₁ , hue C ₂ by exposure to light of wavelength λ ₂ and, after repeating this process, the material becomes a temperature above the glass transition point of the microcapsules, but below the color forming temperature of the heat-sensitive Color forming layer is exposed, followed by forming an image at a temperature above the color forming temperature of the heat-sensitive color forming layer and obtaining a multi-color image. In this case, the multicolor image can be obtained without using microcapsules having different glass transition points.

In this case the difference of the activation wavelengths of the photooxidants is between λ ₁ and λ ₂ , λ ₂ and g ₃ ,. , , and λ _{n -1} and λ _{n are} preferably 20 nm or more, more preferably 50 nm or more.

Photooxidants with different activation wavelengths can also be contained in microcapsules with different glass transition points. In this case, the printing is carried out at a printing temperature T _a , wherein T ₁ T _a < T ₂ , to form a latent image, followed by exposing the material with light of a wavelength λ ₁ and an image with a hue C ₁ receives. Then, at a printing temperature T _b , where T ₂ Tb < T ₃ , a latent image is formed which gives an image with a hue C ₂ in the subsequent exposure to light of a wavelength λ ₂ . In this way a multicolored image is obtained.

The photosensitive, heat-sensitive Color forming layer and the heat-sensitive Color forming layer are in terms of Storage properties of the recording materials and e.g. the color density preferably as separate layers applied the carrier. Also, it is preferable to this Laying layers on the same side of the carrier to simplify the recording device.

Although not limited herein, the heat-sensitive color-forming layer is preferably closer be arranged on the carrier as the photosensitive, heat-sensitive color-forming layer.

The recording material according to the invention can also e.g. with a surface protection layer, a Intermediate layer or a backing layer are provided.

To activate the photooxidants and to Generation of leuco dye images can be any Light sources are used, e.g. fluorescent tubes, Mercury lamps, metal halide lamps, xenon lamps and Tungsten lamps.

The multicolor recording materials according to the invention are characterized by excellent storage properties in the fresh state and good color densities. Since she's out only two layers exist is the manufacturing process quite easy. In the cases where the two Layers formed on the same side of the carrier be further, there is the advantage that the Recording device can be simplified.  

The following examples illustrate the invention. All Parts and percentages are by weight, if nothing else is stated.

Example 1 Preparation of capsule body A

parts Benzo [a] -6-N, N-diethylamino-9- (2-methoxycarbonyl) phenylxanthene 2 2,2'-bis (o-chlorophenyl) -4,4 ', 5,5'-tetraphenylimidazol 2 tribromomethylphenylsulfone 0.4 2,5-di-tert-octylhydroquinone 0.6 p-toluenesulfonamide 0.2 Xylylene diisocyanate / trimethylolpropane adduct, 75% ethyl acetate solution 20

These components become a solvent mixture from 16 parts of ethyl acetate and 18 parts Diisopropylnaphthalene given. The resulting solution is to 54 parts of an aqueous 6% solution of Carboxy-modified polyvinyl alcohol and at Emulsified and dispersed at 20 ° C, with an emulsion with an average particle diameter of 1 micron becomes. 68 parts of water are added to the emulsion, followed by stirring for 3 hours at 40 ° C. The mixture is then cooled to room temperature and filtered to a Capsule fluid A to give.

The glass transition point of the capsule walls is 80 ° C, the Color formation wavelength of the leuco dye and the Photooxidant 365 nm and the hue obtained is magenta.  

Preparation of capsule fluid B

parts Tris (4-diethylamino-o-tolyl) methane 2 2,2'-bis (o-chlorophenyl) -4,4 ', 5,5'-tetraphenylimidazol 2 2,6-di-trichloromethyl-4- (p-methoxyphenyl) triazine 0.8 2- (5'-methyl-2'-hydroxyphenyl) benzotriazole 4 Hexamethylene diisocyanate / trimethylolpropane adduct, 75% ethyl acetate solution 20

These components become a solvent mixture from 16 parts of ethyl acetate and 18 parts Diisopropylnaphthalene given. The resulting solution is to 54 parts of an aqueous 6% solution of Carboxy-modified polyvinyl alcohol and at Emulsified and dispersed at 20 ° C to give an emulsion having a mean particle diameter of 1 μm. 68 parts of water are added to the emulsion, whereupon the mixture is stirred for 3 hours at 40 ° C. By cooling At room temperature and filtration to obtain a Capsule fluid B.

The glass transition point of the capsule walls is 70 ° C, the Color formation wavelength of the leuco dye and the Photooxidant 435 nm and the hue obtained is cyan (cyan).

Preparation of a reducing agent dispersion

30 parts of 1-phenylpyrazolidin-3-one (Phenidone A) become 150 parts of an aqueous 4% solution of carboxy given modified polyvinyl alcohol and in one Transverse sand mill to a Phenidone A dispersion with a mean particle size of 1 micron dispersed.  

Preparation of a photosensitive, heat-sensitive Coloring liquid

A coating liquid for the photosensitive, heat-sensitive layer is composed of 6.8 parts of the Capsule fluid A, 6.8 parts of the capsule fluid B, 6.0 parts of the above Reducing agent dispersion and 0.4 parts of 30% epoxidized Polyamide resin produced.

Producing a heat-sensitive Coloring liquid

20 g of 2,7-di-n-hexyl-3,6-dimethoxyfluoran are added one day together with 100 g of an aqueous 5% polyvinyl alcohol solution dispersed in a ball mill, wherein a color former dispersion with a middle Particle size of not more than 3 microns receives.

This is followed by 20 g of Bisphenol A a day along with 100 g of an aqueous 5% polyvinyl alcohol in a Ball mill dispersed, wherein a developer dispersion having an average particle size of not more than 3 μm receives.

Further, 80 g of calcium carbonate together with 160 g an aqueous 0.5% solution of sodium hexametaphosphate dispersed in a homogenizer, wherein one Pigment dispersion receives.

5 g of the color former dispersion, 10 g of Developer dispersion and 15 g of the pigment dispersion are mixed together and with 3 g of a 21% Zinc stearate dispersion added to a heat-sensitive Produce color forming liquid.

The color formation with this color former and developer starts at 90 ° C.  

Production of a recording material

The heat-sensitive color-forming liquid and the photosensitive, heat-sensitive color-forming liquid are successively coated on a quality paper (basis weight 76 g / m ² ) with a coating bar such that the application amounts (solid components) are 8 g / m ² and 12 g / m ^2, respectively. Drying at 40 ° C gives a multicolor recording material.

The resulting recording material is for 1 second with a heating block at several arbitrary positions 70 ° C heated, whereupon the material with 5 seconds a Jetlight ultra high pressure mercury lamp under Using a filter that emits light of a wavelength of less than 400 nm filters out, totally exposed. in this connection you get a cyan image.

The material will then be in the same way for 1 second a heating block heated to 80 ° C and 5 seconds with the said mercury lamp using a filter, filters out the light with a wavelength over 400 nm, totally exposed. This arises on the photosensitive, heat-sensitive color-forming layer a magenta picture.

Finally, the material will be on it for 1 second Way with a heating block heated to 100 ° C, taking a yellow picture arises.

These results show that color images are in light cyan, Magenta and Yellow and Blue (Cyan + Magenta), Green (Cyan + Yellow), red (magenta + yellow) and black (cyan + magenta + Yellow) can be made.  

A capsule liquid C of the following composition is prepared.

Preparation of Capsule Liquid C

parts Tris (4-diethylamino-o-tolyl) methane 2 2,2'-bis (o-chlorophenyl) -4,4 ', 5,5'-tetraphenylimidazol 2 2,6-di-trichloromethyl-4- (p-methoxyphenyl) triazine 0.8 2- (5'-methyl-2'-hydroxyphenyl) benzotriazole 4 p-toluenesulfonamide 0.2 Xylylene diisocyanate / trimethylolpropane adduct, 75% ethyl acetate solution 20

These components are added to a mixed solvent of 16 parts of ethyl acetate and 18 parts of diisopropylnaphthalene. The resulting solution is added to 54 parts of a 6% aqueous solution of carboxy-modified polyvinyl alcohol and emulsified and dispersed at 20 ° C to obtain an emulsion having an average particle diameter of 1 μm. 68 parts of water are added to the emulsion, after which the mixture is stirred for 3 hours at 40.degree. By cooling to room temperature and filtration, a capsule liquid C is obtained .

The glass transition point of the capsule walls is 80 ° C, the Color formation wavelength of the leuco dye and the Photooxidant 435 nm and the hue obtained is cyan.

A recording material is prepared as in Example 1, but the capsule liquid C is used instead of the capsule liquid B. The thus obtained recording material is imagewise exposed for 5 seconds with a Jetlight ultra-high pressure mercury lamp using a filter which filters out light of less than 400 nm. This gives a cyan image.

The image is then used in the same way of a filter that filters out light above 400 nm imagewise exposed. This turns a magenta image receive.

The recording material with the color images is then at a feed rate of 1 cm / s by heating rollers led by 80 ° C. Finally, you heat the material 1 second using a heating block arbitrary places at 100 ° C, taking a yellow picture arises.

The results show that color images are in clear cyan, Magenta and Yellow and Blue (Cyan + Magenta), Green (Cyan + Yellow), red (magenta + yellow) and black (cyan + magenta + Yellow) can be made.

Claims (9)

1. two-color recording material, characterized in that are applied to a support:

• a) a photosensitive, heat-sensitive color-forming layer containing
  (i) microcapsules containing a leuco dye which gives a color upon oxidation, and a photooxidant, and
  (ii) a reducing agent; and
• b) a heat-sensitive color-forming layer having a color forming temperature different from the glass transition temperature of the microcapsule walls and containing an electron donor leuco dye giving a hue different from the leuco dye in the photosensitive heat-sensitive layer, and an electron acceptor compound which reacts with the electron donor leuco dye to form color.

2. Two-color recording material according to claim 1, characterized in that the photosensitive, heat-sensitive color forming layer and the heat-sensitive color-forming layer on the same Side of the carrier are arranged. 3. Two-color recording material according to claim 1, characterized in that the color formation temperature the heat-sensitive color-forming layer is higher as the glass transition temperature of the polymer walls of the Microcapsules.   4. multicolor recording material, characterized in that are applied to a support:

• a) a photosensitive, heat-sensitive color-forming layer containing
  (i) at least two types of microcapsules, each containing a leuco dye which gives a color upon oxidation, and a photooxidant, and
  (ii) a reducing agent, wherein the polymer walls of the at least two types of microcapsules have different glass transition temperatures and the leuco dyes contained in the microcapsules give different hues to each other, and
• b) a heat-sensitive color-forming layer having a color forming temperature different from the glass transition temperatures of the microcapsule walls and containing an electron donor leuco dye giving a hue different from the leuco dye in the photosensitive, heat-sensitive color forming layer and an electron acceptor compound which reacts with the electron donor leuco dye to form color.

5. multicolor recording material according to claim 4, characterized in that the photosensitive, heat-sensitive color forming layer and the heat-sensitive color-forming layer on the same Side of the carrier are arranged. 6. multicolor recording material according to claim 4, characterized in that the color formation temperature the heat-sensitive color-forming layer is higher  as the glass transition temperature of the polymer walls of the Microcapsules. 7. multicolor recording material, characterized in that are applied to a substrate:

• a) a photosensitive, heat-sensitive color-forming layer containing
  (i) at least two types of microcapsules, each containing a leuco dye which gives a color upon oxidation, and a photooxidant; and (ii) a reducing agent, wherein the leuco dyes contained in the microcapsules give different hues to each other and wherein the Microcapsules contained photooxidant by actinic light
  activated by different wavelengths; and
• b) a heat-sensitive color-forming layer having a color forming temperature different from the glass transition temperatures of the microcapsule walls and containing an electron donor leuco dye giving a hue different from the leuco dye in the photosensitive, heat-sensitive color forming layer, and an electron acceptor compound which reacts with the electron donor leuco dye to form color.

8. multicolor recording material according to claim 7, characterized in that the photosensitive, heat-sensitive color forming layer and the heat-sensitive color-forming layer on the same Side of the carrier are arranged.   9. multicolor recording material according to claim 7, characterized in that the color formation temperature the heat-sensitive color-forming layer is higher as the glass transition temperature of the polymer walls of the Microcapsules.